Process of drying and apparatus therefor.



G. W. MOMULLEN- PROCESS OF DRYING AND APPARATUS THEREFOR.

APPLIOATION FILED APR. 7, 1908. 1,0&O,556. Patented 0ct.8,1912.

2 BHEETB-SHEBT 1.

G. W. MOMULLEN- PROCESS OF DRYING AND APPARATUS THEREFOR.

urmornon nun Ann. 1908. 1 40,556. Patented Oct. 8, 1912 '2 snsnws-snnm a.

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"tJNltTE GEORGE WHITMAN MoM'ULI.|E1\T, OF CHICAGO, ILLINOIS.

PROCESS OF DRYING AND APPARATUS THEREFOR.

Specification of Letters .la tent.

Patented Oct. 8,1912.

Application filed April 7, 1908. Serial No. 425,614.

To all whom 1' i may concern:

to it known that l, Gnonon ll 'nrrai'ax ltlGltllJLLEN, a citizen of the United States. residing at Chicago, in the county of (look and State of Illinois, have invented a cor tain new and Improved Process of Drying and l-\ )paratus .lhere;t:,)r, of which the tollowing is a specification.

This invention consists in an improved process of drying and in apparatus for use in connection therewith, and it has for its salient object to provide a method and ap paratus whereby those materials or substances which are detrimentally a tl'ected by being, kept for any Considerable length oi" time in the presence of a moist warm at-.

mosphere may be effectively dried without incurring such detrin'iental etl'eet'.

Another object of the invention to pro-- vide a method and apparatus whereby the drying of relatively large quantities of ma terial may be etlected with greatv uni'toi'miti' and in a relatively rapid manner, the our tormity of action doubtless contributing to the success of the method in avoiding: spoiling.

in developing a practical method for d rying comminutcd vegetables, particularly sugar beets,-and for drying liquids and semi-solids, peculiarly susceptible to bacteiiological changes, I have discovered that it the material being dried be so treated that tresh supplies of dry or moderately dry air be constantly provided, and the air which olt'ects the drying be bodily separated in the immediate locality and promptly rarried a my from the place where its becomes moisture laden, thus permitting the fresh supply of air to flow in and take its place, the ditliculties dueto bacterial changes are substantially it not entirely overcome. it is, of course, obvious that any method or process which is susceptible of use in a commercial way for drying considemble quantities of materialmust be one that can be so carried out as to etl'ectively subject. large areas the material to the drying treatment simultaneously, and must tart-hen more enable this to be done within a comparatively small space.

l Vith the for going matters in mind, I have devised th method and apparatus eonstituting my present invention, a ready compre ension of which will be had from a dcon thereof as carried out by a suitable apparatus shown and described in the accompanying drawings.

In said drawings--l igure l is a vertical sectional View of a drying chamber containmg apparatus in acct'irdauee with my invention and adapted tor carrying out my method the apparatus being shown chiefly in side elevation; Fin". 2 isa transverse ver tical sectional View taken approximately on line 2-2 of Fig. l, and looking in the direction of the arrows; Fig. 3 is a horizontal sectional view on the indirect line 3-3 of Fig. 1 and looking downwardly.

Describing first the apparatus, within a suitable chamber or incl =sure 't is arranged and comprising as its chief features a series of uprights 3, t, 5 and (3 at each side. a series of cross t'rame members T, 7, and 3, above and below, and suitable longitudinal horizontally disposed frame, members above. and below, as t) and 10, all suitably secured to gether.

.ll designates a l'ieating fluid supply pipe, as for example a. steam pipe, connected with a suitable source of steam, leading into the lower part of the chamber and connecting with theriser .12. With the riser 12 are connected a plurality of llat; horizontally disposed heating coils 1tl.-one 'l'oiueaeh of the several stages or levels at which the dryinn is performed in the chamber. These beating coils are severally so formed as to spread across the chief area of the interior of the drying; clntmber, and they are severally connected, conveniently at the opposite side of he chamber, with an ednetion pipe l t wt ich serves to carry away the water of condensation and whatever steam passes through the system. The several heating coils are conveniently supported by means of cross rods 15 extended through the upright supports 5 and (1 from side to side of the frame.

Upon the 'trame are supported sets of belt pulleys or drums, as '16. 16. there being one set of such pulleys for each heating coil. and the pulleys or drums being; so disposed that a belt, as .ti, ltt, ti 20 and 31 may be mounted on the pulleys and arranged to travel horizontally above and below the respective heating coils. Each belt is preteraliily perforated or consists of a suitableopim structure adapted to permit. passage of the air therethrough; and is longitudinally offset a an upright-frame, desiepiated as a whole 2 short distance. relatively to the 'next subjacent belt, so that material carried by the upper lap of ,one belt. may be carried over and discharged into the next belt below, which in turn similarly discharges it to' the next, and so on dowhiwardly. To drive these several belts, the several shafts 22' I which support the belt pulleys at one end ofi ing belts 24 and 25.

. branch 30.

the machine carry drive belt pulleys 23, which are properly connected so as to drive one another through the medium of connect-- I The lowermost shaft 22 is also providedwith a driving pulley 26, to which power is transmitted from any suitable source. Y

To provide for a suitable. circulation, and

the constant supply and continuous removal.

of a drying gaseous agent, usually atmospheric air, the lower portion of the chamber 1 is provided with a plurality of inlets, as 27 and a set of eduction pipes or conduits is provided which will nowbe described.

- 28 designates a main eduction trunk 'arranged to rise vertically alongside of the supporting fran1e2 and connecting at its lower end'with a lateral extension 28' which extends out through the side wall of the chamber and connects with any suitable exhaust mechanism, as for example an exhaust blower 29. With the side of the trunk 28 is connected a plurality of laterally extend:

ing branches 30,one for each of the sev- --eralstages o f-the drier and arranged to ex; tend horizontally above and at a short dis tance from the upper lap of the correspond- "ing belt. -With each of these lateral branches 30' are'connected longitudinally extending intake pipes 31;- there being shown in the present construction'three such pipes extending in eachdirectionfrom each These intake pipes are as nearly as practicable so disposed above their respective belts as to uniformly divide up the space above said belt, and they are capped at their ends and provided throughouttheir lengths with relatively small in.-

let openings or perforations 32 whereby the moisture laden air is drawn in and conveyed away from practically all points of the material-supporting area or surface of the correspondingdrying belt. The chamber is provided at its upper sidewith a hopper-like inlet 33 of a length corresponding to the width of the belt substantially, and arranged so as to discharge-upon the receiving end'of the uppermost econveyer belt. This hopper is provided witha suitable valve or slide 34 whereby the admission of material is controlled. Similarly a discharge chute 35 is provided at the delivery end of the lowermost conveyer belt which leads out through the bottom wall of the chamber. It will be understood that both the inlet and outlet cpenings'through which the main! isfedwill be maintained substantially sealed, either by the material or by,being' apparatus. I

The apparatus described is, .of course, of

a type suitable for. drying small or comminuted solids, and it will be understood closed during the normal operation of the that for drying fluids or semi-solids the ap j paratus must be correspondingly modified.

The method as carried out by theuse of the apparatus shownproceeds substantially as follows: The beltsbeing driven so as to.

move either very slowly and continuously, or intermittently and from time to time as the drying proceeds, and the heating coils being supplied with steam and the exhausting system being in operation, the material.

drying system. Assuming, then, that the apparatus is in full operatiomthe relatively dry air, entering the several inlet openings distributed over the area of the bottom-of the chamber immediately encounters the lowermost heating coil, is thus warmed and rises against and through the upper lap of the lowermost conveyer belt, and, of course, through the material resting thereon. thus simultaneously heating said material and 'bathing it-in relatively dry air. The warm air, of. course, immediately absorbs moisture from the material, and, owing to the exhausting action of the eduction pipesimmediat'ely above the belt and the natural tendency of the air torise, is immediately after it becomes moisture laden drawn in to the l 110 nearest drawing ofi' pipe and thus effectually separated from the replenishing sup-- ply of air and from contact with the materialibeing acted upon. Of course, other supplies of fresh air flow up along the sides and ends of the chamber, and through and be tween the laps of the several belts, so that whathas been described as taking place as to the material resting upon the upper lap of the lowermost belt is likewise taking place as to the material upon each of the:

several other conveyer belts. In other words, fresh air is being supplied to each of V the several heating coils, is being heated and .carried upwardly through the belt and 4 around the material resting thereon, and m becoming charged with moisture, and is be ing promptly separated and drawn intothe corresponding eduction pipes practically as V soon as moistened, throughout all parts of the apparatus. Moreover, the air which? I 1. The method of drying which consists in i'lisposmg the material to hc'drled in a pluroaches the uppermost parts of the chamlccr i will obviously be somewhat warmer than that which is drawn oil in the lower slag from which it follows that the relc v y moist and undrirtd material which has just entered. the chambcr is subjected to that air which is most effective in absorbing-the moisture, viz: the air which is hottest and at the sumo time dry.

The rate of circulation of the air through tho dryingapparatus may he and is effectually controllei'l by the rate at which the cxhaiissting mechanism is operated; it lining ohvioos'that the more rapidly the air is drawn cit tho more rapidly it will [low in through the inlets to the drying chamber.

it will, of col so, be obvious that the method can be practically carried out with various tforms of apparatus.

1 claim as my invention:

rality oi superposedlongitudinally oil-set spacedcpart relatively thin sheets or layers and Wlllllfi a closed drying chamber, contiouously supplying relatively dry air to said chamber so that it flows to all parts of the material to be dried, continuously and directly heating said air bcncath and in close proxin'iity to each of the several layers or sheets of material, and continuously separating and removing the moisture-laden air from the replenishingsupply of air in the immediate locality Where it becomes ITlOiS' ture laden and substantially as fast as it be comes so laden.

2. An apparatus for drying which consists in a plurality of superimposed endless belts longitudinally offset relative to each other, of means for driving said bolts, :1 closed heating system for locally heating each of said bolls, a plurality of inter-connected perforated pipes for removing the moisture laden air in the immediate locality where it becomes moisture laden, and an exhaust pump cimneclcd to the air pipe system.

(l-llllltflll WHITMAN filclllUhLlW. \Vitnesses Ammn'r l-l (iiRA'VES, Emmn Rosa.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patcin Washington, D. 0. 

